Producers now have the tools (grain carts with load cells, yield monitors, GPS) to do on-farm field research. Additionally, growers are being made aware of more and more products/management options that they might use. One might read farm magazines, talk to neighbors, attend extension and industry presentations, but still wonder whether a particular recommendation would be of benefit. So the question remains. How would this (product, change in management) work on the land that I farm? Tools plus uncertainty equals motivation for an on-farm comparison.
Grove, John H., "On-Farm Field Research: Setting Up a Valid Comparison" (2006). Soil Science News and Views. 182.